超高强度圆钢中的碳化物及可能的氢不可逆俘获位点

Carbides and possible hydrogen irreversible trapping sites in ultrahigh strength round steel.

作者信息

Cheng X Y, Li H, Cheng X B

机构信息

Institute of Materials, Shanghai University, Shanghai 200072, China.

出版信息

Micron. 2017 Dec;103:22-28. doi: 10.1016/j.micron.2017.09.005. Epub 2017 Sep 14.

DOI:10.1016/j.micron.2017.09.005

PMID:28942370

Abstract

The carbides in ultrahigh strength round steel have been investigated by using laser-assisted atom probe tomography (APT) and high resolution transmission electron microscopy (HRTEM) in this paper. Two kinds of carbides are found and one is iron carbide MC, where carbide formation elements Cr, Mn and Mo replace partial Fe, while the other is niobium carbide MC, where M includes V and Mo besides Nb. These two carbides, due to their different evaporation field, have various densities in reconstructed image of APT. After correction, the hydrogen content within these two carbides illustrates that MC cannot trap hydrogen, while MC can. The different behaviors in trapping hydrogen between these two carbides may result from elements Fe or Cr in MC carbide having weaker affinity for hydrogen than Nb and V have in MC.

摘要

本文采用激光辅助原子探针层析成像（APT）和高分辨率透射电子显微镜（HRTEM）对超高强度圆钢中的碳化物进行了研究。发现了两种碳化物，一种是碳化铁MC，其中碳化物形成元素Cr、Mn和Mo取代了部分Fe，另一种是碳化铌MC，其中M除了Nb还包括V和Mo。由于这两种碳化物具有不同的蒸发场，在APT重建图像中具有不同的密度。校正后，这两种碳化物中的氢含量表明MC不能捕获氢，而MC可以。这两种碳化物在捕获氢方面的不同行为可能是由于MC碳化物中的元素Fe或Cr对氢的亲和力比MC中的Nb和V弱。